A. Field of the Invention
The present invention relates to a method of removing offensive ammoniac odor from the meat of sharks.
B. Description of the Prior Art
In contrast with the odorless meat of some species of sharks such as a dogfish (Squalus suckleyi) and angelfish, the meat of the majority species of sharks such as a Port Jackson shark, saw shark (Pristiophorus japonicus), requiem shark (Carcharhinus gangeticus) and hammerhead shark begins to give out strong ammoniac odor immediately after death. Because of this unpleasant odor, the use of these sharks has so far been restricted within narrow ranges. Apart from the fins of these sharks which are dried and used as material for Chinese dishes, the only use of these sharks for food has been to boil the meat of these sharks while it is very fresh and make it into fish-paste products, and the only use of the livers of these sharks has been to make liver oil therefrom. All the attempts made in finding new uses for the meat of these sharks have met with failure. By way of example, the strong ammoniac odor could not be kept down even when the fresh meat of these sharks was put up in cans.
The strong ammoniac odor given out by the meat of these sharks is not attributable to the proteolysis caused by putrefaction but to the dissolution of nonprotein nitrogenous compounds, especially urea and trimethylamine oxides, which are contained in larger quantities in the meat of these sharks than in the meat of other odorless sharks or fishes other than sharks.